User initiated break-away clutching of a surgical mounting platform

ABSTRACT

Robotic and/or surgical devices, systems, and methods include kinematic linkage structures and associated control systems configured to facilitate preparation of the system for use. A set-up mode employs an intuitive user interface in which one or more joints of the kinematic linkage are initially held static by a brake or joint drive system. The user may articulate the joint(s) by manually pushing against the linkage with a force, torque, or the like that exceeds a manual articulation threshold. Articulation of the moving joints is facilitated by modifying the signals transmitted to the brake or drive system. The system may sense completion of the reconfiguration from a velocity of the joint(s) falling below a threshold, optionally for a desired dwell time. Embodiments of the invention can provide for manual movement of a platform supporting a plurality of surgical manipulators or the like without having to add additional input devices.

RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 13/967,594, filed Aug. 15, 2013, and claims priority to U.S.Provisional Patent Application No. 61/683,626, filed Aug. 15, 2012, theentire contents of each of which are incorporated herein by reference.

BACKGROUND

Minimally invasive medical techniques are intended to reduce the amountof extraneous tissue that is damaged during diagnostic or surgicalprocedures, thereby reducing patient recovery time, discomfort, anddeleterious side effects. One effect of minimally invasive surgery, forexample, is reduced post-operative hospital recovery times. Because theaverage hospital stay for a standard surgery is typically significantlylonger than the average stay for an analogous minimally invasivesurgery, increased use of minimally invasive techniques could savemillions of dollars in hospital costs each year. While many of thesurgeries performed each year in the United States could potentially beperformed in a minimally invasive manner, only a portion of the currentsurgeries use these advantageous techniques due to limitations inminimally invasive surgical instruments and the additional surgicaltraining involved in mastering them.

Minimally invasive robotic surgical or telesurgical systems have beendeveloped to increase a surgeon's dexterity and avoid some of thelimitations on traditional minimally invasive techniques. Intelesurgery, the surgeon uses some form of remote control (e.g., aservomechanism or the like) to manipulate surgical instrument movements,rather than directly holding and moving the instruments by hand. Intelesurgery systems, the surgeon can be provided with an image of thesurgical site at a surgical workstation. While viewing a two or threedimensional image of the surgical site on a display, the surgeonperforms the surgical procedures on the patient by manipulating mastercontrol devices, which in turn control motion of the servo-mechanicallyoperated instruments.

The servomechanism used for telesurgery will often accept input from twomaster controllers (one for each of the surgeon's hands) and may includetwo or more robotic arms on each of which a surgical instrument ismounted. Operative communication between master controllers andassociated robotic arm and instrument assemblies is typically achievedthrough a control system. The control system typically includes at leastone processor that relays input commands from the master controllers tothe associated robotic arm and instrument assemblies and back from theinstrument and arm assemblies to the associated master controllers inthe case of, for example, force feedback or the like. One example of arobotic surgical system is the DA VINCI® system available from IntuitiveSurgical, Inc. of Sunnyvale, Calif.

A variety of structural arrangements can be used to support the surgicalinstrument at the surgical site during robotic surgery. The drivenlinkage or “slave” is often called a robotic surgical manipulator, andexemplary linkage arrangements for use as a robotic surgical manipulatorduring minimally invasive robotic surgery are described in U.S. Pat.Nos. 7,594,912; 6,758,843; 6,246,200; and 5,800,423; the fulldisclosures of which are incorporated herein by reference. Theselinkages often make use of a parallelogram arrangement to hold aninstrument having a shaft. Such a manipulator structure can constrainmovement of the instrument so that the instrument pivots about a remotecenter of manipulation positioned in space along the length of the rigidshaft. By aligning the remote center of manipulation with the incisionpoint to the internal surgical site (for example, with a trocar orcannula at an abdominal wall during laparoscopic surgery), an endeffector of the surgical instrument can be positioned safely by movingthe proximal end of the shaft using the manipulator linkage withoutimposing potentially dangerous forces against the abdominal wall.Alternative manipulator structures are described, for example, in U.S.Pat. Nos. 7,763,015; 6,702,805; 6,676,669; 5,855,583; 5,808,665;5,445,166; and 5,184,601; the full disclosures of which are incorporatedherein by reference.

A variety of structural arrangements can also be used to support andposition the robotic surgical manipulator and the surgical instrument atthe surgical site during robotic surgery. Supporting linkage mechanisms,sometimes referred to as set-up joints, or set-up joint arms, are oftenused to position and align each manipulator with the respective incisionpoint in a patient's body. The supporting linkage mechanism facilitatesthe alignment of a surgical manipulator with a desired surgical incisionpoint and targeted anatomy. Exemplary supporting linkage mechanisms aredescribed in U.S. Pat. Nos. 6,246,200 and 6,788,018, the fulldisclosures of which are incorporated herein by reference.

While the new telesurgical systems and devices have proven highlyeffective and advantageous, still further improvements are desirable. Ingeneral, improved minimally invasive robotic surgery systems aredesirable. It would be particularly beneficial if these improvedtechnologies enhanced the efficiency and ease of use of robotic surgicalsystems. For example, it would be particularly beneficial to increasemaneuverability, improve space utilization in an operating room, providea faster and easier set-up, inhibit collisions between robotic devicesduring use, and/or reduce the mechanical complexity and size of thesenew surgical systems.

BRIEF SUMMARY

The following presents a simplified summary of some embodiments of theinvention in order to provide a basic understanding of the invention.This summary is not an extensive overview of the invention. It is notintended to identify key/critical elements of the invention or todelineate the scope of the invention. Its sole purpose is to presentsome embodiments of the invention in a simplified form as a prelude tothe more detailed description that is presented later.

The present invention generally provides improved robotic and/orsurgical devices, systems, and methods. Kinematic linkage structures andassociated control systems described herein are particularly beneficialin helping system users to arrange the robotic structure in preparationfor use, including in preparation for a surgical procedure on aparticular patient. Exemplary robotic surgical systems described hereinmay have one or more kinematic linkage sub-systems that are configuredto help align a manipulator structure with the surgical work site. Thejoints of these set-up systems may be actively driven, passive (so thatthey are manually articulated and then locked into the desiredconfiguration while the manipulator is used therapeutically), or a mixof both. Embodiments of the robotic systems described herein may employa set-up mode in which one or more joints are initially held static by abrake or joint drive system. Inadvertent articulation is limited by thebrake or drive system, but the user can manually articulate the joint(s)by manually pushing against the linkage with a force, torque, or thelike that exceeds a manual articulation threshold of the joint(s). Oncethe joint(s) begin to move, a processor may facilitate articulation withless user effort by modifying the signals transmitted to the brake ordrive system. When the user arrives at a desired configuration, thesystem may sense that the user has completed the reconfiguration from avelocity of the joint(s) below a threshold, optionally for a desireddwell time. The system may then again inhibit inadvertent articulationof the joint(s. The dwell time can help avoid locking the linkage whenreversing directions, and the system can provide a “detent” like manualarticulation that is not limited to mechanically pre-defined detentjoint configurations. Embodiments of the invention provide a userinterface is intuitive, and can be particularly well-suited for manualmovement of a platform supporting a plurality of surgical manipulatorsin a robotic surgical system or the like without having to addadditional input devices.

In a first aspect, the invention provides a method for configuring arobotic system. The method comprises inhibiting manual articulation of alinkage of the system from a first pose in response to a first manualeffort against the linkage being below a desired articulation threshold.A manual movement of the linkage from the first pose toward a secondpose is facilitated in response to a second manual effort to articulatethe linkage exceeding the desired articulation threshold. The secondpose is determined in response to the manual movement of the linkage.Manual movement of the linkage from the second pose is inhibited.

Thus, in a first aspect, a method for configuring a robotic system isprovided. The method includes inhibiting manual articulation of alinkage of the system from a first pose in response to a first manualeffort against the linkage, facilitating a manual movement of thelinkage from the first pose toward a second pose, determining the secondpose in response to the manual movement of the linkage, and inhibitingmanual movement of the linkage from the second pose. The inhibiting stepis in response to a first manual effort against the linkage that isbelow a desired articulation threshold. The facilitating step is inresponse to a second manual effort against the linkage that exceeds thedesired articulation threshold.

In other exemplary embodiments, a joint sensor may sense a first torqueof the first manual effort applied to a joint and a processor mayinhibit the manual articulation by determining drive signals configuredto induce a counteracting torque to the linkage opposing the firsttorque so as to urge the linkage back toward the first pose. In furtherembodiments, the joint sensor may also sense the second torque of thesecond manual effort applied to the joint and the processor may beconfigured to determine that the second effort exceeds the desiredarticulation threshold. For example, in some embodiments thearticulation threshold may be a torque threshold and the processor maydetermine that the second effort exceeds the desired articulationthreshold by determining that the second torque exceeds the thresholdtorque. In response to a second effort exceeding the desiredarticulation threshold, the processor may alter the drive signals so asto decrease the counteracting torque so that the first torque issufficient to manually move the manipulator.

In some embodiments of the method, a processor may alter drive signalsin response to the second effort exceeding the desired articulationthreshold by adding a friction compensation component to the drivesignals so as to mitigate friction of the linkage for the manualmovement toward the second pose.

In other embodiments, the second pose may be determined by determiningthat a velocity of the manual movement is below a threshold velocity.Additionally, the second pose may also be determined by determining thatthe velocity of the manual movement remains below the threshold velocityfor a threshold dwell time so as to facilitate reversing a direction ofthe movement without inhibiting manual movement.

In further embodiments, the method for configuring a robotic systemincludes driving the linkage in the second pose with drive signals so asto inhibit manual movement of the linkage from the second pose inresponse to a third manual effort against the manipulator being belowthe desired articulation threshold.

The above exemplary methods may be used to configure a surgical roboticsystem. For example, the linkage may be a set-up structure having aproximal base and a platform with the joint disposed therebetween. Theplatform may support a plurality of surgical manipulators, where eachmanipulator may be an instrument holder configured to releasably receivea surgical instrument. The manual movement may be a movement that alterspositions of the plurality of manipulators relative to a surgical site.In another example, the linkage may be included in a surgicalmanipulator having a holder for releasably receiving a surgicalinstrument. The surgical manipulator may also include a cannulainterface configured for releasably receiving a cannula. The manipulatormay be further configured to pivotably move a shaft of the instrumentwithin an aperture adjacent the cannula so as to manipulate an endeffector of the instrument within a minimally invasive surgicalaperture. The configuration method may further include inhibiting manualarticulation of the joint with manual effort exceeding the desiredarticulation threshold in response to the mounting of the cannula to thecannula interface.

In another aspect, a robotic system is provided. The robotic systemincludes a linkage having a joint, a drive or brake system coupled tothe linkage, and a processor coupled with the drive or brake system. Theprocessor may be configured to transmit signals to the drive or brakesystem so as to inhibit manual articulation of the linkage from a firstpose in response to a first manual effort against the linkage beingbelow a desired articulation threshold. The processor may alter thesignals in response to a second manual effort to articulate the linkageexceeding the desired articulation threshold. The altered signals may beconfigured to facilitate a manual movement of the linkage from the firstpose toward a second pose. The processor may also determine the secondpose in response to the manual movement of the linkage and may transmitthe signals to the drive system so as to inhibit manual movement of thelinkage from the second pose.

In additional exemplary embodiments, the robotic system further includesa joint sensor coupled to the joint. The joint sensor may be configuredto sense a first torque of the first manual effort applied to the joint.The processor may be configured to determine the signals so as to applya counteracting torque to the linkage opposing the first torque and urgethe linkage back toward the first pose. In particular embodiments, adrive or brake system may include a drive system. Further, the jointsensor may be configured so as to transmit to the processor a secondtorque of the second manual effort applied to the joint. The processormay be further configured to determine if the second effort exceeds thedesired articulation threshold using the second torque. For example, theprocessor may be configured to determine that the second effort exceedsthe desired articulation threshold by determining whether the secondtorque exceeds a threshold torque. In response to a second effortexceeding the desired articulation threshold, the processor may alterthe drive signals so as to decrease the counteracting torque so that thefirst torque is sufficient to manually move the manipulator.

In some embodiments, the signals of the robotic system may include drivesignals and the processor may be configured to alter the drive signalsin response to the second effort exceeding the desired articulationthreshold by adding a friction compensation component to the drivesignals so as to mitigate friction of the linkage for the manualmovement toward the second pose.

The processor may be configured to determine a second pose in responseto a velocity of the manual movement being below a threshold velocity.The processor may be further configured to determine the second pose bydetermining that the velocity of the manual movement is below thethreshold velocity for a threshold dwell time so as to facilitate areversal of a direction of the manual movement without inhibiting themanual movement. The processor may also be configured to inhibit manualmovement of the linkage from the second pose in response to a thirdmanual effort against the manipulator being below the desiredarticulation threshold.

The above exemplary system may be a surgical robotic system. Forexample, the linkage may be a set-up structure having a proximal baseand a platform with the joint disposed therebetween. The platform maysupport a plurality of surgical manipulators, where each manipulator maybe an instrument holder configured to releasably receive a surgicalinstrument. The manual movement may be a movement that alters positionsof the plurality of manipulators relative to a surgical site. In anotherexample, the linkage may be included in a surgical manipulator having aholder for releasably receiving a surgical instrument. The surgicalmanipulator may also include a cannula interface configured forreleasably receiving a cannula. The manipulator may be furtherconfigured to pivotably move a shaft of the instrument within anaperture adjacent the cannula so as to manipulate an end effector of theinstrument within a minimally invasive surgical aperture. The system mayfurther include inhibiting manual articulation of the joint with manualeffort exceeding the desired articulation threshold in response to themounting of the cannula to the cannula interface.

In an additional aspect, a robotic surgical system is provided. Therobotic surgical system includes a linkage having a joint, a drivesystem coupled to the linkage, a torque sensor system coupled to thejoint, and a processor coupling the torque sensor with the drive system.The joint may be disposed between a proximal base and an instrumentholder. The instrument holder may be configured for releasablysupporting a surgical instrument. The processor is configured totransmit drive signals to the drive system so as to inhibit manualarticulation of the joint from a first configuration in response to asensed torque being below a desired articulation threshold. In responseto a sensed torque exceeding the desired articulation threshold, theprocessor may alter the drive signals to facilitate a manual movement ofthe joint from the first configuration toward a second configurationusing a movement torque lower than the articulation threshold. Inresponse to a velocity of the manual movement being below a thresholdvelocity, the processor may determine the second configuration. Theprocessor may also be configured to transmit drive signals to the drivesystem so as to inhibit manual movement of the linkage from the secondpose in response to a sensed torque being below a desired articulationthreshold.

In another aspect, a method of configuring a robotic system is provided.The method includes driving a robotic assembly during manual efforts tomove a linkage of the assembly so as to simulate a first and seconddetent of the linkage at first and second linkage poses. The method alsoincludes determining the second pose in response to a manual movement ofthe linkage to the second pose.

For a fuller understanding of the nature and advantages of the presentinvention, reference should be made to the ensuing detailed descriptionand accompanying drawings. Other aspects, objects and advantages of theinvention will be apparent from the drawings and detailed descriptionthat follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a minimally invasive robotic surgery systembeing used to perform a surgery, in accordance with many embodiments.

FIG. 2 is a perspective view of a surgeon's control console for arobotic surgery system, in accordance with many embodiments.

FIG. 3 is a perspective view of a robotic surgery system electronicscart, in accordance with many embodiments.

FIG. 4 diagrammatically illustrates a robotic surgery system, inaccordance with many embodiments.

FIG. 5A is a partial view of a patient side cart (surgical robot) of arobotic surgery system, in accordance with many embodiments.

FIG. 5B is a front view of a robotic surgery tool, in accordance withmany embodiments.

FIG. 6 is a perspective schematic representation of a robotic surgerysystem, in accordance with many embodiments.

FIG. 7 is a perspective schematic representation of another roboticsurgery system, in accordance with many embodiments.

FIG. 8 shows a robotic surgery system, in accordance with manyembodiments, in conformance with the schematic representation of FIG. 7.

FIG. 9 illustrates rotational orientation limits of set-up linkagesrelative to an orienting platform of the robotic surgery system of FIG.8.

FIG. 10 shows a center of gravity diagram associated with a rotationallimit of the boom assembly for a robotic surgery system, in accordancewith many embodiments.

FIG. 11 is a flow chart schematically illustrating a method forpreparing a robotic surgical system for surgery.

DETAILED DESCRIPTION

In the following description, various embodiments of the presentinvention will be described. For purposes of explanation, specificconfigurations and details are set forth in order to provide a thoroughunderstanding of the embodiments. However, it will also be apparent toone skilled in the art that the present invention may be practicedwithout the specific details. Furthermore, well-known features may beomitted or simplified in order not to obscure the embodiment beingdescribed.

The kinematic linkage structures and control systems described hereinare particularly beneficial in helping system users to arrange therobotic structure of a procedure on a particular patient. Along withactively driven manipulators used to interact with tissues and the likeduring treatment, robotic surgical systems may have one or morekinematic linkage systems that are configured to support and help alignthe manipulator structure with the surgical work site. These set-upsystems may be actively driven or may be passive, so that they aremanually articulated and then locked into the desired configurationwhile the manipulator is used therapeutically. The passive set-upkinematic systems may have advantages in size, weight, complexity, andcost. Unfortunately, a plurality of manipulators may be used to treattissues of each patient, the manipulators may each independently benefitfrom accurate positioning so as to allow the instrument supported bythat instrument to have the desired motion throughout the workspace, andminor changes in the relative locations of adjacent manipulators mayhave significant impact on the interactions between manipulators (withpoorly positioned manipulators potentially colliding or having theirrange and/or ease of motion significantly reduced). Hence, thechallenges of quickly arranging the robotic system in preparation forsurgery can be significant.

One option is to mount multiple manipulators to a single platform, withthe manipulator-supporting platform sometimes being referred to as anorienting platform. The orienting platform can be supported by anactively driven support linkage (sometimes referred to herein as aset-up structure, and typically having a set-up structure linkage, etc.)The system may also provide and control motorized axes of the roboticset-up structure supporting the orienting platform with some kind ofjoystick or set of buttons that would allow the user to actively drivethose axes as desired in an independent fashion. This approach, whileuseful in some situations, may suffer from some disadvantages. Inparticular, it may be difficult to locate a drive button for all theelements of a complex system so that each is accessible to usersapproaching the system in all its potential configurations. Whileindividual clutch buttons might also be used to release the brake ordrive system, the possibility of confusion may remain between buttonshaving different functions. Furthermore, both sterile and non-sterilemembers of a surgical team may want to articulate some joints orlinkages (such as by grabbing differing locations inside or outside thesterile field). Hence a more intuitive and flexible user interface wouldbe desirable. This is particularly true of an orienting platform for usein multi-quadrant surgery, or for a structure that supports a pluralityof surgical manipulators and may pivot about an axis extending at leastroughly vertically so as to orient the manipulators relative to apatient on a surgical table or other support.

Minimally Invasive Robotic Surgery

Referring now to the drawings, in which like reference numeralsrepresent like parts throughout the several views, FIG. 1 is a plan viewillustration of a Minimally Invasive Robotic Surgical (MIRS) system 10,typically used for performing a minimally invasive diagnostic orsurgical procedure on a Patient 12 who is lying down on an Operatingtable 14. The system can include a Surgeon's Console 16 for use by aSurgeon 18 during the procedure. One or more Assistants 20 may alsoparticipate in the procedure. The MIRS system 10 can further include aPatient Side Cart 22 (surgical robot) and an Electronics Cart 24. ThePatient Side Cart 22 can manipulate at least one removably coupled toolassembly 26 (hereinafter simply referred to as a “tool”) through aminimally invasive incision in the body of the Patient 12 while theSurgeon 18 views the surgical site through the Console 16. An image ofthe surgical site can be obtained by an endoscope 28, such as astereoscopic endoscope, which can be manipulated by the Patient SideCart 22 to orient the endoscope 28. The Electronics Cart 24 can be usedto process the images of the surgical site for subsequent display to theSurgeon 18 through the Surgeon's Console 16. The number of surgicaltools 26 used at one time will generally depend on the diagnostic orsurgical procedure and the space constraints within the operating roomamong other factors. If it is necessary to change one or more of thetools 26 being used during a procedure, an Assistant 20 may remove thetool 26 from the Patient Side Cart 22, and replace it with another tool26 from a tray 30 in the operating room.

FIG. 2 is a perspective view of the Surgeon's Console 16. The Surgeon'sConsole 16 includes a left eye display 32 and a right eye display 34 forpresenting the Surgeon 18 with a coordinated stereo view of the surgicalsite that enables depth perception. The Console 16 further includes oneor more input control devices 36, which in turn cause the Patient SideCart 22 (shown in FIG. 1) to manipulate one or more tools. The inputcontrol devices 36 can provide the same degrees of freedom as theirassociated tools 26 (shown in FIG. 1) to provide the Surgeon withtelepresence, or the perception that the input control devices 36 areintegral with the tools 26 so that the Surgeon has a strong sense ofdirectly controlling the tools 26. To this end, position, force, andtactile feedback sensors (not shown) may be employed to transmitposition, force, and tactile sensations from the tools 26 back to theSurgeon's hands through the input control devices 36.

The Surgeon's Console 16 is usually located in the same room as thepatient so that the Surgeon may directly monitor the procedure, bephysically present if necessary, and speak to an Assistant directlyrather than over the telephone or other communication medium. However,the Surgeon can be located in a different room, a completely differentbuilding, or other remote location from the Patient allowing for remotesurgical procedures.

FIG. 3 is a perspective view of the Electronics Cart 24. The ElectronicsCart 24 can be coupled with the endoscope 28 and can include a processorto process captured images for subsequent display, such as to a Surgeonon the Surgeon's Console, or on another suitable display located locallyand/or remotely. For example, where a stereoscopic endoscope is used,the Electronics Cart 24 can process the captured images to present theSurgeon with coordinated stereo images of the surgical site. Suchcoordination can include alignment between the opposing images and caninclude adjusting the stereo working distance of the stereoscopicendoscope. As another example, image processing can include the use ofpreviously determined camera calibration parameters to compensate forimaging errors of the image capture device, such as optical aberrations.

FIG. 4 diagrammatically illustrates a robotic surgery system 50 (such asMIRS system 10 of FIG. 1). As discussed above, a Surgeon's Console 52(such as Surgeon's Console 16 in FIG. 1) can be used by a Surgeon tocontrol a Patient Side Cart (Surgical Robot) 54 (such as Patent SideCart 22 in FIG. 1) during a minimally invasive procedure. The PatientSide Cart 54 can use an imaging device, such as a stereoscopicendoscope, to capture images of the procedure site and output thecaptured images to an Electronics Cart 56 (such as the Electronics Cart24 in FIG. 1). As discussed above, the Electronics Cart 56 can processthe captured images in a variety of ways prior to any subsequentdisplay. For example, the Electronics Cart 56 can overlay the capturedimages with a virtual control interface prior to displaying the combinedimages to the Surgeon via the Surgeon's Console 52. The Patient SideCart 54 can output the captured images for processing outside theElectronics Cart 56. For example, the Patient Side Cart 54 can outputthe captured images to a processor 58, which can be used to process thecaptured images. The images can also be processed by a combination theElectronics Cart 56 and the processor 58, which can be coupled togetherto process the captured images jointly, sequentially, and/orcombinations thereof. One or more separate displays 60 can also becoupled with the processor 58 and/or the Electronics Cart 56 for localand/or remote display of images, such as images of the procedure site,or other related images.

Processor 58 will typically include a combination of hardware andsoftware, with the software comprising tangible media embodying computerreadable code instructions for performing the method steps of thecontrol functionally described herein. The hardware typically includesone or more data processing boards, which may be co-located but willoften have components distributed among the robotic structures describedherein. The software will often comprise a non-volatile media, and couldalso comprise a monolithic code but will more typically comprise anumber of subroutines, optionally running in any of a wide variety ofdistributed data processing architectures.

FIGS. 5A and 5B show a Patient Side Cart 22 and a surgical tool 62,respectively. The surgical tool 62 is an example of the surgical tools26. The Patient Side Cart 22 shown provides for the manipulation ofthree surgical tools 26 and an imaging device 28, such as a stereoscopicendoscope used for the capture of images of the site of the procedure.Manipulation is provided by robotic mechanisms having a number ofrobotic joints. The imaging device 28 and the surgical tools 26 can bepositioned and manipulated through incisions in the patient so that akinematic remote center is maintained at the incision to minimize thesize of the incision. Images of the surgical site can include images ofthe distal ends of the surgical tools 26 when they are positioned withinthe field-of-view of the imaging device 28.

Surgical tools 26 are inserted into the patient by inserting a tubularcannula 64 through a minimally invasive access aperture such as anincision, natural orifice, percutaneous penetration, or the like.Cannula 64 is mounted to the robotic manipulator arm and the shaft ofsurgical tool 26 passes through the lumen of the cannula. Themanipulator arm may transmit signals indicating that the cannula hasbeen mounted thereon.

Robotic Surgery Systems and Modular Manipulator Supports

FIG. 6 is a perspective schematic representation of a robotic surgerysystem 70, in accordance with many embodiments. The surgery system 70includes a mounting base 72, a support linkage 74, an orienting platform76, a plurality of outer set-up linkages 78 (two shown), a plurality ofinner set-up linkages 80 (two shown), and a plurality of surgicalinstrument manipulators 82. Each of the manipulators 82 is operable toselectively articulate a surgical instrument mounted to the manipulator82 and insertable into a patient along an insertion axis. Each of themanipulators 82 is attached to and supported by one of the set-uplinkages 78, 80. Each of the outer set-up linkages 78 is rotationallycoupled to and supported by the orienting platform 76 by a first set-uplinkage joint 84. Each of the inner set-up linkages 80 is fixedlyattached to and supported by the orienting platform 76. The orientingplatform 76 is rotationally coupled to and supported by the supportlinkage 74. And the support linkage 74 is fixedly attached to andsupported by the mounting base 72.

In many embodiments, the mounting base 72 is a movable and floorsupported, thereby enabling selective repositioning of the overallsurgery system 70, for example, within an operating room. The mountingbase 72 can include a steerable wheel assembly and/or any other suitablesupport features that provide for both selective repositioning as wellas selectively preventing movement of the mounting base 72 from aselected position. The mounting base 72 can also have other suitableconfigurations, for example, a ceiling mount, fixed floor/pedestalmount, a wall mount, or an interface configured for being supported byany other suitable mounting surface.

The support linkage 74 is operable to selectively position and/or orientthe orienting platform 76 relative to the mounting base 72. The supportlinkage 74 includes a column base 86, a translatable column member 88, ashoulder joint 90, a boom base member 92, a boom first stage member 94,a boom second stage member 96, and a wrist joint 98. The column base 86is fixedly attached to the mounting base 72. The translatable columnmember 88 is slideably coupled to the column base 86 for translationrelative to column base 86. In many embodiments, the translatable columnmember 88 translates relative to the column base 86 along a verticallyoriented axis. The boom base member 92 is rotationally coupled to thetranslatable column member 88 by the shoulder joint 90. The shoulderjoint 90 is operable to selectively orient the boom base member 92 in ahorizontal plane relative to the translatable column member 88, whichhas a fixed angular orientation relative to the column base 86 and themounting base 72. The boom first stage member 94 is selectivelytranslatable relative to the boom base member 92 in a horizontaldirection, which in many embodiments is aligned with both the boom basemember 92 and the boom first stage member 94. The boom second stagemember 96 is likewise selectively translatable relative to the boomfirst stage member 94 in a horizontal direction, which in manyembodiments is aligned with the boom first stage member 94 and the boomsecond stage member 96. Accordingly, the support linkage 74 is operableto selectively set the distance between the shoulder joint 90 and thedistal end of the boom second stage member 96. The wrist joint 98rotationally couples the distal end of the boom second stage member 96to the orienting platform 76. The wrist joint 98 is operable toselectively set the angular orientation of the orienting platform 76relative to the mounting base 72.

Each of the set-up linkages 78, 80 is operable to selectively positionand/or orient the associated manipulator 82 relative to the orientingplatform 76. Each of the set-up linkages 78, 80 includes a set-uplinkage base link 100, a set-up linkage extension link 102, a set-uplinkage parallelogram linkage portion 104, a set-up linkage verticallink 106, a second set-up linkage joint 108, and a manipulator supportlink 110. In each of the set-up linkage base links 100 of the outerset-up linkages 78 can be selectively oriented relative to the orientingplatform 76 via the operation of the a first set-up linkage joint 84. Inthe embodiment shown, each of the set-up linkage base links 100 of theinner set-up linkages 80 is fixedly attached to the orienting platform76. Each of the inner set-up linkages 80 can also be rotationallyattached to the orienting platform 76 similar to the outer set-uplinkages via an additional first set-up linkage joints 84. Each of theset-up linkage extension links 102 is translatable relative to theassociated set-up linkage base link 100 in a horizontal direction, whichin many embodiments is aligned with the associated set-up linkage baselink and the set-up linkage extension link 102. Each of the set-uplinkage parallelogram linkage portions 104 configured and operable toselectively translate the set-up linkage vertical link 106 in a verticaldirection while keeping the set-up linkage vertical link 106 verticallyoriented. In example embodiments, each of the set-up linkageparallelogram linkage portions 104 includes a first parallelogram joint112, a coupling link 114, and a second parallelogram 116. The firstparallelogram joint 112 rotationally couples the coupling link 114 tothe set-up linkage extension link 102. The second parallelogram joint116 rotationally couples the set-up linkage vertical link 106 to thecoupling link 114. The first parallelogram joint 112 is rotationallytied to the second parallelogram joint 116 such that rotation of thecoupling link 114 relative to the set-up linkage extension link 102 ismatched by a counteracting rotation of the set-up linkage vertical link106 relative to the coupling link 114 so as to maintain the set-uplinkage vertical link 106 vertically oriented while the set-up linkagevertical link 106 is selectively translated vertically. The secondset-up linkage joint 108 is operable to selectively orient themanipulator support link 110 relative to the set-up linkage verticallink 106, thereby selectively orienting the associated attachedmanipulator 82 relative to the set-up linkage vertical link 106.

FIG. 7 is a perspective schematic representation of a robotic surgerysystem 120, in accordance with many embodiments. Because the surgerysystem 120 includes components similar to components of the surgerysystem 70 of FIG. 6, the same reference numbers are used for similarcomponents and the corresponding description of the similar componentsset forth above is applicable to the surgery system 120 and is omittedhere to avoid repetition. The surgery system 120 includes the mountingbase 72, a support linkage 122, an orienting platform 124, a pluralityof set-up linkages 126 (four shown), and a plurality of the surgicalinstrument manipulators 82. Each of the manipulators 82 is operable toselectively articulate a surgical instrument mounted to the manipulator82 and insertable into a patient along an insertion axis. Each of themanipulators 82 is attached to and supported by one of the set-uplinkages 126. Each of the set-up linkages 126 is rotationally coupled toand supported by the orienting platform 124 by the first set-up linkagejoint 84. The orienting platform 124 is rotationally coupled to andsupported by the support linkage 122. And the support linkage 122 isfixedly attached to and supported by the mounting base 72.

The support linkage 122 is operable to selectively position and/ororient the orienting platform 124 relative to the mounting base 72. Thesupport linkage 122 includes the column base 86, the translatable columnmember 88, the shoulder joint 90, the boom base member 92, the boomfirst stage member 94, and the wrist joint 98. The support linkage 122is operable to selectively set the distance between the shoulder joint90 and the distal end of the boom first stage member 94. The wrist joint98 rotationally couples the distal end of the boom first stage member 94to the orienting platform 124. The wrist joint 98 is operable toselectively set the angular orientation of the orienting platform 124relative to the mounting base 72.

Each of the set-up linkages 126 is operable to selectively positionand/or orient the associated manipulator 82 relative to the orientingplatform 124. Each of the set-up linkages 126 includes the set-uplinkage base link 100, the set-up linkage extension link 102, the set-uplinkage vertical link 106, the second set-up linkage joint 108, atornado mechanism support link 128, and a tornado mechanism 130. Each ofthe set-up linkage base links 100 of the set-up linkages 126 can beselectively oriented relative to the orienting platform 124 via theoperation of the associated first set-up linkage joint 84. Each of theset-up linkage vertical links 106 is selectively translatable in avertical direction relative to the associated set-up linkage extensionlink 102. The second set-up linkage joint 108 is operable to selectivelyorient the tornado mechanism support link 128 relative to the set-uplinkage vertical link 106

Each of the tornado mechanisms 130 includes a tornado joint 132, acoupling link 134, and a manipulator support 136. The coupling link 134fixedly couples the manipulator support 136 to the tornado joint 132.The tornado joint 130 is operable to rotate the manipulator support 136relative to the tornado mechanism support link 128 around a tornado axis136. The tornado mechanism 128 is configured to position and orient themanipulator support 134 such that the remote center of manipulation (RC)of the manipulator 82 is intersected by the tornado axis 136.Accordingly, operation of the tornado joint 132 can be used to reorientthe associated manipulator 82 relative to the patient without moving theassociated remote center of manipulation (RC) relative to the patient.

FIG. 8 is a simplified representation of a robotic surgery system 140,in accordance with many embodiments, in conformance with the schematicrepresentation of the robotic surgery system 120 of FIG. 7. Because thesurgery system 140 conforms to the robotic surgery system 120 of FIG. 7,the same reference numbers are used for analogous components and thecorresponding description of the analogous components set forth above isapplicable to the surgery system 140 and is omitted here to avoidrepetition.

The support linkage 122 is configured to selectively position and orientthe orienting platform 124 relative to the mounting base 72 via relativemovement between links of the support linkage 122 along multiple set-upstructure axes. The translatable column member 88 is selectivelyrepositionable relative to the column base 86 along a first set-upstructure (SUS) axis 142, which is vertically oriented in manyembodiments. The shoulder joint 90 is operable to selectively orient theboom base member 92 relative to the translatable column member 88 arounda second SUS axis 144, which is vertically oriented in many embodiments.The boom first stage member 94 is selectively repositionable relative tothe boom base member 92 along a third SUS axis 146, which ishorizontally oriented in many embodiments. The wrist joint 98 isoperable to selectively orient the orienting platform 124 relative tothe boom first stage member 94 around a fourth SUS axis 148, which isvertically oriented in many embodiments.

Each of the set-up linkages 126 is configured to selectively positionand orient the associated manipulator 82 relative to the orientingplatform 124 via relative movement between links of the set-up linkage126 along multiple set-up joint (SUJ) axes. Each of the first set-uplinkage joint 84 is operable to selectively orient the associated set-uplinkage base link 100 relative to the orienting platform 124 around afirst SUJ axis 150, which in many embodiments is vertically oriented.Each of the set-up linkage extension links 102 can be selectivelyrepositioned relative to the associated set-up linkage base link 10along a second SUJ axis 152, which is horizontally oriented in manyembodiments. Each of the set-up linkage vertical links 106 can beselectively repositioned relative to the associated set-up linkageextension link 102 along a third SUJ axis 154, which is verticallyoriented in many embodiments. Each of the second set-up linkage joints108 is operable to selectively orient the tornado mechanism support link128 relative to the set-up linkage vertical link 106 around the thirdSUJ axis 154. Each of the tornado joints 132 is operable to rotate theassociated manipulator 82 around the associated tornado axis 138.

FIG. 9 illustrates rotational orientation limits of the set-up linkages126 relative to the orienting platform 124, in accordance with manyembodiments. Each of the set-up linkages 126 is shown in a clockwiselimit orientation relative to the orienting platform 124. Acorresponding counter-clockwise limit orientation is represented by amirror image of FIG. 9 relative to a vertically-oriented mirror plane.As illustrated, each of the two inner set-up linkages 126 can beoriented from 5 degrees from a vertical reference 156 in one directionto 75 degrees from the vertical reference 156 in the opposite direction.And as illustrated, each of the two outer set-up linkages can beoriented from 15 degrees to 95 degrees from the vertical reference 156in a corresponding direction.

In use, it will often be desirable for a surgical assistant, surgeon,technical support, or other user to configure some or all of thelinkages of robotic surgical system 140 for surgery, including theset-up structure linkage, the set-up joints, and/or each of themanipulators. Included among the task in configuring these linkages willbe positioning the orienting platform 124 relative to first stage member94 about vertical fourth SUS axis 148 of wrist joint 98. A joint drivemotor 121 and/or brake system 123 is coupled to wrist joint 98, with oneexemplary embodiment including both a drive 121 and brake 123.Additionally, a joint sensor system will typically sense an angularconfiguration or position of wrist joint 98.

An exemplary user interface, system, and method for manually configuringthe system for use will be described herein with reference to manualarticulation of orienting platform 124 by articulation of wrist joint 98about fourth SUS axis 148, as schematically illustrated by arrow 127. Itshould be understood that alternative embodiments may be employed toarticulate one or more alternative joints of the overall kinematicsystem, including one or more alternative joints of the set-upstructure, one or more of the set-up joints, or one or more of thejoints of the manipulators linkages. Use of the exemplary embodiment forarticulating the motorized wrist joint embodiments may allow a user toefficiently position manipulators 82. The manual articulation of wristjoint 98 as described herein can improve speed and ease of use whilemanually docking manipulators 82 to their associated cannulas 64, asshown in FIG. 5B.

FIG. 10 shows a center of gravity diagram associated with a rotationallimit of a support linkage for a robotic surgery system 160, inaccordance with many embodiments. With components of the robotic surgerysystem 160 positioned and oriented to shift the center-of-gravity 162 ofthe robotic surgery system 160 to a maximum extent to one side relativeto a support linkage 164 of the surgery system 160, a shoulder joint ofthe support linkage 164 can be configured to limit rotation of thesupport structure 164 around a set-up structure (SUS) shoulder-jointaxis 166 to prevent exceeding a predetermined stability limit of themounting base.

FIG. 11 schematically illustrates a method for positioning orientingplatform 124 by articulating wrist joint 98. As generally describedabove, robotic system 140 may be used in a master following mode totreat tissues and the like. The robotic system will typically haltfollowing, and will start 131 a configuration mode which allows a userto manually configure the orienting platform in a desired orientationabout fourth SUS axis 148. Once the configuration mode has been entered,the current angle θ_(C) of wrist joint 98, as sensed by the joint sensorsystem, is set as the desired angle θ_(D) in step 133. If a cannula ismounted to any of the manipulators supported by platform 124, the systemmay apply the brake to the wrist joint and exit the configuration modeso as to inhibit manual movement of the wrist joint via step 135.

While in the configuration mode, when the platform is not moving aboutthe wrist joint the system processor will typically transmit signals tothe joint motor associated with wrist joint 98 so as to maintain the setdesired angle θ_(D). Hence, when the system is bumped, pushed, or pulledlightly the wrist motor may urge the platform back toward the desiredangle by applying a joint torque per an error E that varies with thedifference between the sensed joint position and the desired jointposition:E=θ−θ _(D)This driving of the joint toward the desired pose in step 137 will oftenbe limited to allow a user to overcome the servoing of the wrist jointby applying sufficient effort 139 against the linkage system. Forexample, when the joint sensing system indicates a displacement of thejoint beyond a threshold amount, when the torque being applied to themotor to counteract the applied force reaches a threshold amount, when asensed force applied to the linkage system distally of the joint exceedsa threshold amount, or the like, the processor may halt servoing of thewrist joint to counteract articulation of the joint. In some embodimentsthere may be a time element of the effort threshold to overcome theservoing, such as by halting servoing in response to a torque thatexceeds a threshold for a time that exceeds a threshold. Still otheroptions are possible, including more complex relationships between thethreshold force or torque and time, sensing that the force is applied toa particular linkage or subset of linkages supported by the wrist (orother articulatable joint), and the like. In an exemplary embodiment, ajoint sensor between the orienting platform and the rest of the setupstructure system provides a signal used to estimate torque applied tothe orienting platform, and the joint displacement and servo stiffnessare used to estimate a disturbance torque applied to the surgical armsand/or setup joints. In an additional exemplary embodiment, the errorsignal may be filtered so as to make the system more sensitive totransient pushes than slow or steady-state signals. Such error filteringmay make the trigger more sensitive while limiting false triggers whenthe setup structure is on a sloped surface.

When a user pushes or pulls on one or more of the surgical manipulators,the set-up joint linkages, or directly on the platform with an effortsufficient to exceed the desired articulation threshold the user is ableto rotate the orienting platform without having to fight the servocontrol. Although servoing so as to counteract the user movement of theplatform is halted in step 141, drive signals may still be sent to thewrist motor. For example, friction compensation, gravity compensation,momentum compensation, and or the like may be provided 143 by applyingappropriate drive signals during manual movement of the platform.Exemplary compensation drive systems are more fully described in U.S.Patent Publication 2009/0326557 in the name of Neimeyer and entitled“Friction Compensation in a Minimally Invasive Surgical Apparatus,” inU.S. Patent Publication 2011/0009880 in the name of Prisco et al. andentitled “Control System for Reducing Internally Generated Frictionaland Inertial Resistance to Manual Positioning of a SurgicalManipulator,” and the like. In some embodiments, the system may employjoint range of motion limits alone or in addition to the drive signalswhen servoing is halted. Such range of motion limits may respond similarto servoing when a user pushes beyond a range motion limit except theyare one sided.

Once the user has manually articulated the wrist near the desiredorientation, the user will tend to slow the platform down and uponreaching the desired configuration will halt movement of the platform.The system takes advantage of this, and as the joint sensor indicatesthat movement of the platform falls below a desired threshold of zerothe processor may, in response, re-set the desired joint angle andre-initiate servoing (or braking) so as to inhibit movement from thatjoint position. As the user may want to reverse direction of the manualjoint articulation to correct any overshoot, the processor may notre-engage the servo until the articulation speed remains below athreshold for a desired dwell period.

Other variations are within the spirit of the present invention. Thus,while the invention is susceptible to various modifications andalternative constructions, certain illustrated embodiments thereof areshown in the drawings and have been described above in detail. It shouldbe understood, however, that there is no intention to limit theinvention to the specific form or forms disclosed, but on the contrary,the intention is to cover all modifications, alternative constructions,and equivalents falling within the spirit and scope of the invention, asdefined in the appended claims.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. The terms “comprising,” “having,” “including,” and “containing”are to be construed as open-ended terms (i.e., meaning “including, butnot limited to,”) unless otherwise noted. The term “connected” is to beconstrued as partly or wholly contained within, attached to, or joinedtogether, even if there is something intervening. Recitation of rangesof values herein are merely intended to serve as a shorthand method ofreferring individually to each separate value falling within the range,unless otherwise indicated herein, and each separate value isincorporated into the specification as if it were individually recitedherein. All methods described herein can be performed in any suitableorder unless otherwise indicated herein or otherwise clearlycontradicted by context. The use of any and all examples, or exemplarylanguage (e.g., “such as”) provided herein, is intended merely to betterilluminate embodiments of the invention and does not pose a limitationon the scope of the invention unless otherwise claimed. No language inthe specification should be construed as indicating any non-claimedelement as essential to the practice of the invention.

Preferred embodiments of this invention are described herein, includingthe best mode known to the inventors for carrying out the invention.Variations of those preferred embodiments may become apparent to thoseof ordinary skill in the art upon reading the foregoing description. Theinventors expect skilled artisans to employ such variations asappropriate, and the inventors intend for the invention to be practicedotherwise than as specifically described herein. Accordingly, thisinvention includes all modifications and equivalents of the subjectmatter recited in the claims appended hereto as permitted by applicablelaw. Moreover, any combination of the above-described elements in allpossible variations thereof is encompassed by the invention unlessotherwise indicated herein or otherwise clearly contradicted by context.

All references, including publications, patent applications, andpatents, cited herein are hereby incorporated by reference to the sameextent as if each reference were individually and specifically indicatedto be incorporated by reference and were set forth in its entiretyherein.

What is claimed is:
 1. A medical device comprising: a linkage; a driveunit coupled to the linkage; and a processor coupled with the driveunit, the processor being configured: to cause, in response to a firstmanual effort against the linkage below an articulation threshold, thedrive unit to inhibit manual articulation of the linkage from a firstpose of the linkage; to cause, in response to a second manual effortagainst the linkage exceeding the articulation threshold, the drive unitto facilitate a manual articulation of the linkage from the first poseof the linkage toward a second pose of the linkage; in response todetermining that a velocity of the manual articulation of the linkage isbelow a threshold velocity, to determine that the linkage is at thesecond pose of the linkage; and to cause, in response to the determiningthat the linkage is at the second pose of the linkage, the drive unit toinhibit manual articulation of the linkage from the second pose of thelinkage.
 2. The medical device of claim 1, further comprising: a jointsensor coupled to a joint of the linkage, the joint sensor beingconfigured to sense a first torque applied by the first manual effortagainst the joint and transmit the first torque to the processor; theprocessor being further configured to cause, in response to receivingthe first torque, the drive unit to apply a counteracting torque to thejoint that opposes the first torque and urges the linkage toward thefirst pose of the linkage.
 3. The medical device of claim 2, wherein:the joint sensor is further configured to sense a second torque appliedby the second manual effort against the joint and transmit the secondtorque to the processor, and the processor is further configured to:determine, in response to receiving the second torque, that the secondtorque exceeds the articulation threshold; and cause, in response to thedetermining that the second torque exceeds the articulation threshold,the drive unit to decrease the counteracting torque on the joint so thatthe first torque is sufficient to manually move the linkage.
 4. Themedical device of claim 3, wherein the processor is further configuredto determine that the second manual effort exceeds the articulationthreshold when the second torque exceeds a threshold torque.
 5. Themedical device of claim 3, wherein the processor is further configuredto filter the second torque to increase sensitivity to transients in thesecond manual effort.
 6. The medical device of claim 1, wherein theprocessor is further configured to cause the drive unit to mitigate oneor more of friction of the linkage during the manual articulation towardthe second pose of the linkage, effects of gravity on the linkage, andmomentum of the linkage.
 7. The medical device of claim 1, wherein theprocessor is further configured to determine that the velocity of themanual articulation is below the threshold velocity for a thresholddwell time before determining that the linkage is at the second pose ofthe linkage.
 8. The medical device of claim 7, wherein the processor isfurther configured to cause the drive unit to facilitate a reversal of adirection of the manual articulation without inhibiting the manualarticulation until the manual articulation has been below the thresholdvelocity for the threshold dwell time.
 9. The medical device of claim 1,wherein the processor is further configured to cause the drive unit toinhibit the manual articulation from the second pose of the linkagewhile a third manual effort against the linkage remains below thearticulation threshold.
 10. The medical device of claim 1, wherein: thelinkage comprises a set-up structure having a proximal base, a platform,and a joint between the proximal base and the platform; and the platformsupports a plurality of surgical manipulators, each manipulatorcomprising an instrument holder configured to releasably receive asurgical instrument; and the manual articulation from the first pose tothe second pose alters positions of the plurality of surgicalmanipulators relative to a surgical site.
 11. The medical device ofclaim 1, wherein: the linkage includes a surgical manipulator having aninstrument holder and a cannula interface, the instrument holder beingconfigured to releasably receive a surgical instrument, and the cannulainterface being configured to releasably receive a cannula; the surgicalmanipulator is configured to pivotably move a shaft of the surgicalinstrument within a minimally invasive surgical aperture adjacent thecannula so as to manipulate an end effector of the surgical instrument;and the processor is further configured to cause, in response to thecannula being mounted to the cannula interface, the drive unit toinhibit manual articulation of the linkage by a third manual effortagainst the linkage exceeding the articulation threshold.
 12. Themedical device of claim 1, wherein: the drive unit comprises a brake,and the processor is further configured to cause the drive unit toinhibit the manual articulation of the linkage from the first pose, fromthe second pose, or from the first and second poses of the linkage byapplying the brake.
 13. The medical device of claim 1, wherein thearticulation threshold comprises a torque.
 14. The medical device ofclaim 1, wherein the articulation threshold comprises a force.
 15. Themedical device of claim 1, wherein the processor is further configuredto apply range of motion limits of the linkage while causing the driveunit to facilitate the manual articulation of the linkage from the firstpose of the linkage toward the second pose of the linkage.
 16. Themedical device of claim 1, wherein the processor is further configuredto delay causing the drive unit to facilitate the manual articulation ofthe linkage from the first pose of the linkage toward the second pose ofthe linkage until the second manual effort against the linkage exceedsthe articulation threshold for a predetermined period of time.
 17. Themedical device of claim 1, wherein the processor is further configuredto cause, in response to receiving a signal that the linkage is coupledto a cannula, the drive unit to inhibit manual articulation of thelinkage from the first or second pose of the linkage by a third manualeffort against the linkage exceeding the articulation threshold.
 18. Amethod of operating a medical device, the method comprising: inhibitinga first manual articulation of a linkage of the medical device from afirst pose of the linkage by driving the linkage against a first manualeffort below an articulation threshold against the linkage; facilitatingthe first manual articulation of the linkage from the first pose towarda second pose by driving the linkage in response to a second manualeffort above the articulation threshold against the linkage; determiningthe linkage is at the second pose by determining that a velocity of thefirst manual articulation of the linkage is below a threshold velocity;and inhibiting a second manual articulation of the linkage from thesecond pose by driving the linkage against a third manual effort belowthe articulation threshold against the linkage.
 19. The method of claim18, further comprising: sensing a first torque applied by the firstmanual effort against a joint of the linkage; and applying acounteracting torque to the joint that opposes the first torque to urgethe linkage toward the first pose of the linkage.
 20. The method ofclaim 19, further comprising: sensing a second torque applied by thesecond manual effort against the joint; determining that the secondtorque exceeds the articulation threshold; and decreasing thecounteracting torque on the joint so that the first torque is sufficientto manually move the linkage.
 21. The method of claim 18, furthercomprising determining that the velocity of the first manualarticulation is below the threshold velocity for a threshold dwell timebefore determining that the linkage is at the second pose of thelinkage.
 22. The method of claim 18, wherein inhibiting the first manualarticulation of the linkage from the first pose of the linkage comprisesapplying a brake.
 23. The method of claim 18, further comprising:receiving a signal that the linkage is mounted to a cannula; andinhibiting, in response to receiving the signal, manual articulation ofthe linkage from the first or second pose of the linkage by a thirdmanual effort against the linkage exceeding the articulation threshold.